31317023521 has 12 divisors (see below), whose sum is σ = 36442059888. Its totient is φ = 26834281992.

The previous prime is 31317023477. The next prime is 31317023533. The reversal of 31317023521 is 12532071313.

It is not a de Polignac number, because 31317023521 - 2⁹ = 31317023009 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31317023521.

It is not an unprimeable number, because it can be changed into a prime (31317020521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46090 + ... + 254476.

It is an arithmetic number, because the mean of its divisors is an integer number (3036838324).

Almost surely, 2^31317023521 is an apocalyptic number.

It is an amenable number.

31317023521 is a deficient number, since it is larger than the sum of its proper divisors (5125036367).

31317023521 is a wasteful number, since it uses less digits than its factorization.

31317023521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211468 (or 211461 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 28.

Adding to 31317023521 its reverse (12532071313), we get a palindrome (43849094834).

The spelling of 31317023521 in words is "thirty-one billion, three hundred seventeen million, twenty-three thousand, five hundred twenty-one".